Method for injecting a liquid additive into poultry flesh

ABSTRACT

POULTRY CARCASSES ARE TREATED TO IMPROVE THE EATING QUALITIES, NOTABLY FLAVOR, TENDERNESS, JUICINESS, AND FAT CONTENT, BY INJECTING AN ADDITIVE, SUCH AS A VEGETABLE OIL EMULSION, INTO THE MEAT TISSUE OF THE BREAST AREAS BY INSERTING A HOLLOW NEEDLE INTO THE FLESH FROM LOCATIONS EXPOSED AT EITHER OF THE POSTERIOR AND ANTERIOR VISCERAL INCISIONS. IN THIS WAY THE NEEDLE CAN BE INSERTED ALONG A   PATH THAT IS GENERALLY NORMAL TO THE TISSUE FIBER STRUCTURE SO AS TO RELEASE THE ADDITIVE IN DIRECTIONS ALIGNED WITH AND BETWEEN THE FIBERS. ALSO THE INJECTION CAN BE MADE WITHOUT PENETRATIONG THE SKIN OF THE FOWL WHEREBY THERE WILL BE SUBSTANTIALLY LESS OPPORTUNITY FOR THE ADDITIVE TO OOZE FROM THE TISSUE.

Jan. 19, 1971 E. J. sTRAN'blNE ETAL 3,556,809

METHOD FOR INJECTING A LIQUID ADDI'IIVE INTO POULTRY FLESH 2Sheets-Sheet 1 Original Filed April 1, 1968 ELOON J. STRAND/IVE CHARLESW PECKENPAUGH INVIJN'IORS.

A TTOPNEY.

19,1971 E. J. STRANDINE ET AL 3,556,8Q9 METHOD FOR INJECLTING A LIQUIDADDITIVE INTO POULTRY FLESH Original Filed April 1, 1968 2 SheetsSheet 2ELDON a. STRAND/NE CHARLES w PECKENPAUGH INVENI'ORS.

ATTORNEY.

United States Patent 3,556,809 METHOD FOR INJECTING A LIQUID ADDITIVEINTO POULTRY FLESH Eldon J. Strandine, Chicago, Ill., and Charles W.Peckenpaugh, Detroit Lakes, Minn., assingors to Swift & Company,Chicago, 111., a corporation of Delaware Original application Apr. 1,1968, Ser. No. 717,803, now Patent No. 3,511,164, dated May 12, 1970.Divided and this application Nov. 19, 1969, Ser. No. 871,325

Int. Cl. A22c 21/00 U.S. C]. 99-107 3 Claims ABSTRACT OF THE DISCLOSUREPoultry carcasses are treated to improve the eating qualities, notablyflavor, tenderness, juiciness, and fat content, by injecting anadditive, such as a vegetable oil emulsion, into the meat tissue of thebreast areas by inserting a hollow needle into the flesh from locationsexposed at either of the posterior and anterior visceral incisions. Inthis way the needle can be inserted along a path that is generallynormal to the tissue fiber structure so as to release the additive indirections aligned with and between the fibers. Also the injection canbe made without penetrating the skin of the fowl whereby there will besubstantially less opportunity for the additive to ooze from the tissue.

This application is a division of our co-pending application Ser. No.717,803, filed Apr. 1, 1968, now Pat. No. 3,511,164 issued May 12, 1970.

This invention relates to method and apparatus for improving the eatingqualities of poultry; and more specifically relates to a method andapparatus for injecting a treating agent or additive, such as an ediblefat or oil, into poultry flesh.

The prior art teaches the injection of various additives into poultryflesh as being beneficial. For example, the Tichy Pat. No. 2,418,914teaches various materials, including butter, to be beneficial wheninjected into meat or poultry by high-pressure spray that passes thematerial into the flesh apparently without breaking the skin. Earlierthe Mareta Pat. No. 2,128,952 taught that seasoning materials could beinjected through a hollow needle inserted through the skin into theflesh of poultry. More recently, the Nelson Pat. No. 3,035,508 hastaught a multiple needle injecting device for introducing liquidformulas at various points on a poultry carcass; and the Schwall et al.Pat. No. 3,366,491 has taught that fat may be injected into poultry insuch a way as to purposely exude therefrom during cooking.

With the exception of the Tichy patent, the prior art has involvedtechniques that result in openings in the poultry skin through which anadditive is introduced and through which the additive may subsequentlyescape. Tichy, however, introduces such materials apparently Withoutbreaking the skin, but does so only in localized areas and with arelatively expensive piece of equipment. However, it is believed to beof significant advantage to be able to introduce an additive throughouta relatively large portion of poultry flesh in a manner whereby theadditive will be substantially wholly retained therein. Retention of theadditive is primarily beneficial to eating qualities, but also improvesthe appearance of poultry intended for the consumer market, as comparedto the prior art, by avoiding a greasy surface condition which isparticularly unattractive when the carcass is packaged in transparentfilm.

Accordingly, it is a principal objective of the present invention toprovide an improved method and apparatus for introducing an additive topoultry flesh whereby the additive will be retained therein andprevented from escape.

It is another object of the present invention to provide an improvedmethod and apparatus for introducing an additive such as a fat or oil tothe white meat or breast area of poultry in a more even and uniformdistribution without puncturing or breaking the poultry skin.

It is still another object of the present invention to provide animproved method and apparatus for injecting an additive into thePectoralis superficialis muscle of a poultry carcass.

It is yet another object of the present invention to provide an improvedmethod and apparatus for injecting an additive into the breast area of apoultry carcass in an economical and efficient manner.

Generally, the present invention comprises the position ing of aneviscerated fowl before an operator who then manually displaces thesevered skin at either the anterior (crop) or posterior (ventral)visceral incisions, so as to expose the flesh of the Pectoralissuperficialis muscle, and then penetrating the flesh in a generallyhorizontal and longitudinal direction with a relatively long hollowneedle. The process is continued by pushing the needle through the fleshthrough almost the entire length of the breast area and then, while inplace, injecting an additive through V a plurality of spaced orificesalong the needle body. Thereafter the needle is withdrawn and thedisplaced skin released to return to normal position covering the entrysite. The invention can also be applied, with advantage, to the breastportions of poultry after removal from a carcass.

An apparatus devised for performance of the foregoing method comprises arelatively long, hollow needle having a closed pointed end and aplurality of spaced orifices located laterally along the body of theneedle. Preferably a guide member is also spaced outwardly from theneedle and is congruent therewith so as to regulate the depth of theneedle in the flesh by sliding along the skin of the fowl.

Further objects and advantages will become apparent upon reading thefollowing detailed specification in conjunction with the drawings where:

FIG. 1 is a profile view of a poultry carcass showing a preferred lineof penetration in phantom;

FIG. 2 is a top view of a poultry carcass showing the lines ofpenetration; and

FIG. 3 is a perspective view of a preferred apparatus of the presentinvention.

The present invention is mainly directed to the injection of an additivematerial into the flesh of a poultry carcass. Preferably the additive isintended to moisturize and tenderize the drier portions of poultryflesh. To that end, it is preferred to use an emulsion of vegetable oil,particularly of coconut oil, that will congeal rapidly when injectedinto a chilled carcass. It is the nature of cooked white meat of poultryto be of a dry texture. Poultry dark meat is relatively moist, whencooked, as compared to the white meat, and benefits relatively littlefrom the addition of such an ingredient. The white flesh of turkeybenefits to the greatest extent from the injection of an additive suchas a moisturizing agent, particularly the Pectoralis superficialis whichbecomes even dryer during cooking. The Pectoralis profundus, whichunderlies the superficialis muscle, is benefitted to a lesser extent asit also is normally juicier and is ofter referred to as the tenderloinof poultry. Accordingly, the greatest benefit of the present inventionis obtained when it is practiced on the breast meat of turkeys; althoughadvantage is also obtained where practiced on other fowl.

With reference to the application of the invention to turkeys, it is tobe noted in FIG. 1 that a turkey carcass generally 10 when rested uponits back disposes the breast areas upwardly and exposes the verydistinct keelbone 12 ridge structure. In processing turkeys and otherfowl, the carcass is usually eviscerated immediately after slaughter bymaking an incision in the ventral or posterior area of the bird wherebone structure is absent. This is normally in a direct line with thekeelbone 12. In FIG. 1 the posterior area is identified by referencecharacter =14.

Similarly, certain of the evisceration steps are performed on theforward or anterior portion of the carcass and a similar incision isnormally found in the crop area 16 of the bird.

Other notable conformation features of a poultry carcass are thewishbone 18 (shown in phantom in FIG. 1) and the breast tissue thatoverlays each side of the bird from approximately the wishbonerearwardly and directly beside the keelbone 12. The large body and majorexterior portion of breast tissue is known as the Pectoralissuperficialis muscle 20. A smaller muscle known as the Pectoralisprofundus is located beneath the Pectoralis superficialis in a smallarea lying against the lower portion of the keelbone (the Pectoralisprofundus is not shown in the drawings). The tissue fibers of the breastmeat, and particularly of the Pectoralis superficialis 20, run generallyfrom the keelbone 12 downwardly toward each wing of the bird.

We have found that the poultry tissue is more receptive to an additivematerial if the additive can be directed, for the most part, between thetissue fibers. Thus we have devised a means by which an additive such asan edible fat or oil can be injected in a multitude of small streamsdirected parallel to the tissue fibers. To accomplish this, one or moreentry or injection channels are made generally longitudinally (withrespect to the orientation of the carcass) in the breast tissue of eachside of a carcass. While as many as four such channels may beconveniently made, satisfactory results have been achieved with a singlechannel in each breast. Also, it is preferred to create the channelwithout penetrating the skin of the carcass so that escape of theinjected material through the channel will be retarded by the overlying,intact skin.

Accordingly, the carcass, after evisceration, is first placed on itsback and the skin displaced outwardly from either the anterior orposterior evisceral openings. We prefer to use the posterior openingarea because at the time of injection the bird should be at leastpartially chilled and prior to that time the giblets, neck, etc., willhave been bagged and placed within the crop or anterior opening. Evenafter the legs of the bird have been trussed, access may be had to theposterior opening. However, because of the conformation of the flesh offowls, the posterior area presents a smaller target. The anterior orcrop area presents a rather thick area of breast tissue and would be thebetter choice for penetration if the present invention were to bepracticed earlier in the processing of the fowl.

The longitudinal channel is made by inserting a hollow needlesubstantially lengthwise of the breast tissue. Where a single channel isto be made in each breast area, it is preferable to keep it entirelywithin the Pectoralis superficialis muscle 20. If the channel shouldpenetrate the area between the Pectoralis superficialis and Pectoralisprofundus muscles, there will be a tendency for the injected additive tocollect at the interface of those muscles and not be distributeduniformly. Where multiple channels are selected, one or more can bedirected specifically to each of the Pectoralis superficialis andPectoralis profundus muscles.

Thus, a hollow needle having a plurality of lateral openings is insertedsubstantially through the length of the Pectoralis superficialis muscle.Because the muscle becomes quite shallow at the posterior end of thebird an entry site 22 is preferably located about 1 to 2 inches forwardof the rearmost portion of the keelbone 12 and about /2 to 2 inchesbelow the outer edge thereof. The needle is inserted at this point andaimed to run toward the wishbone 18 at a depth varying from /2 to 1 inchbe- Cal low the skin. Penetration is terminated about /2. inch short ofthe wishbone 18.

The hollow needle includes a plurality of orifices at opposite lateralsides thereof so that when in place an additive can be forced from theorifices outwardly in the general direction of the upper edge of thekeelbone l2 and the lower portion (or back side) of the carcass. Becausethe breast tissue is substantially thicker at the forward area of thecarcass adjacent the wishbone, and thinner at the rear portion, theorifices in the needle should be more closely spaced and/ or ofrelatively larger diameter in the areas that will be inserted to theforward end of the bird; and relatively broadly spaced and/ or smallerin diameter in the rear areas. Also, where the needle is to be insertedfrom the posterior end of the bird it preferably will have no orificesalong that portion of the needle that will extend approximately 1 inchforward of the entry point 22 into the flesh. Otherwise there will be atendency for any additive injected within this area of minimum flesh tobe immediately expelled through the channel made by the needle.

The additive material is injected while the needle is held in place.Usually from 3% to 6% by weight of the carcass of an additive may beinjected. The maximum amount is normally controlled by governmentregulation. We have found that approximately 3 by weight of an oilemulsion comprising approximately 84% coconut oil, 12% Water, 3% salt,and the remainder of emulsifiers, flavor and coloring agents, producevery desirable improvements in the cooked flesh.

After the injection of liquid is complete, the needle is withdrawnsmoothly so as not to enlarge the opening at the entry point 2.2 and theskin of the bird is then released to return to its normal position. Theskin will thus cover the entry site and further hinder any tendency forthe injected material to ooze therefrom. The above described emulsion isof further advantage in this regard as it sets up very sharply and thuswill not ooze from the injection site.

If it is elected to inject the breast tissue from the anterior end ofthe bird, it is merely necessary to similarly displace the skin of thecrop opening and insert a needle generally centrally of the exposedflesh. Again, the needle should be directed substantially horizontallyof the bird, while resting upon its back, from an entry point 24 nearthe breastbone to a point just short of a point that would be selectedfor posterior injection and without penetrating the flesh surface andskin. However, when it is intended to inject the bird from the anteriorend, it is preferred to employ a needle whereon the orifices arearranged generally opposite from that of the previously describedneedle. That is, the orifices are more widely spaced or of smallerdiameter near the pointed end (which will reach the shallow area of thePectoralis superficialis muscle) and more closely spaced or of largerdiameter at the opposite portion of the needle (which will reside in thethicker portion of the flesh near the wishbone 18). The additive is theninjected and the needle withdrawn.

Where injecting from either the posterior or anterior end of thecarcass, it will be seen that the preferred entry channel or path ofinsertion is substantially along a horizontal line (when the carcass isresting upon its back) extending between about the breastbone and apoint /2 to 2 inches below and forward of the rearmost portion of thekeelbone 12. The preferred line of penetration is shown in phantom onFIGS. 1 and 2.

A preferred apparatus for performing the foregoing method is shown inFIG. 3. The illustrated apparatus has two similar portions specificallydevised for injection of both breasts of a turkey from the posteriorincision. Each portion comprises a relatively long, hollow needle 30having a closed pointed end 32. and a plurality of spaced lateralorifices 34 arranged in two courses along two opposite sides of theneedle. An additional course of orifices 36 may be located along an areaof the needle between the two lateral courses of orifices 34. Where anadditional course of orifices 36 is employed, the orifices 36 preferablyare staggered from orifices 34. Normally the needle 30 should bepositioned so that when inserted into the poultry flesh the lateralorifices 34 will be generally aimed parallel to the tissue fibers, andthe additional course of orifices 36 will be aimed inwardly of thecarcass.

Preferably a guide member 38 is arranged parallel with the needle 30 andheld spaced therefrom by a lug 40 mounted upon a barrel fitting 42 towhich the needle is assembled. The guide 38 may be slightly shorter thanthe needle and is spaced therefrom a distance equal to the maximum depthof penetration desired for the needle beneath the poultry skin. It isalso possible, although not necessary, that the needle may be slightlycurved so as to approximate the contour of the breast tissue of acarcass. If the needle 30 is curved, the guide 38 should be similarlycurved so as to be congruent with the needle; and the additional courseof orifices 36 should be located in the concave surface area. Preferablythe needle is manufactured of a slightly flexible stainless steel andwill thus curve somewhat as it is inserted through the flesh.Furthermore it is possible to cause the needles to diverge slightly asthey are advanced through the flesh so that as the points reach theanterior portions they will spread into the lower and thicker parts ofthe breast tissue.

A handle 44 is usually secured to the barrel 42 for convenience of anoperator to manipulate the needle 30. A flexible hose 46 is connected tothe needle 30 behind the barrel 42 and runs to a source of pressurizedadditive. Preferably a one-way check valve 48 is located between thebarrel 42 and hose 46.

The source of additive may conveniently be a metering pump of a typewell known in the art. However, a highly desirable source, whichconstitutes a separate invention, includes a plurality of meteringcylinders 50, one or more of which are connected to a needle 30 by thehose 46. Each metering cylinder has an associated piston (not shown)that is driven by a piston rod 52 in turn connected by a yoke 54 to apower cylinder 56. The latter is controllable with regard to length ofstroke and thereby controls the amount of material expelled from eachmetering cylinder 50. Air lines 58, 60 are connected to the forward andrear ends of the power cylinder 56 and to a control means 62 by whichpressurized air is appropriately directed to control the stroke of yoke54 in accordance with a preestablished setting or in accordance with asignal representing the weight of the fowl being treated. Suitable checkvalves 64 and conduits 66 connect each metering cylinder to a supply ofadditive (not shown) so as to automatically refill the cylinder 50 whenthe piston therein is moved rearwardly.

The preferred form of apparatus as shown in FIG. 3' includes two of theabove described needle assemblies ganged to a single handle forsimultaneous insertion in both 'breast areas of a single carcass. Thisis preferably done by mounting each barrel 42 upon one end of separateL- shaped mounting brackets 68 which have elongated slots 70 at theopposite ends. Two such brackets are fastened together by a nut and bolt72 run through each of the slots 70. A suspension bracket 74 is alsoconnected by the same bolt 72 to the mounting brackets 68; and thehandle 44 is secured to the former. Also an eyelet 76 at the top of thesuspension bracket 74 conveniently receives a counter-weightedsuspension wire 78 to support most of the weight of the apparatus. Theslotted mounting brackets 68 allow for adjustment of the distancebetween needles 30 so as to conform the apparatus to the body shape ofdifferent types and weight ranges of birds. The brackets 68 may also beavailable in varying sizes to provide even wider adjustments in the sizeof the apparatus; and similarly the needles should be available invarying lengths.

As an illustration, we have found that most sizes of turkeys can beprocessed with needles inch outside diameter and small, medium or largelengths being 4 inches, 5%; inches, and 6 inches, respectively, plus apointed tip of inch. We prefer to equally space plural orifices at /2inch centers commencing inch to the rear of the point for the lateralorifices and inch for the offset orifices. Where the needles are to beinserted from the posterior of a bird a first number of .045 inchdiameter orifices are located nearer the point and a second number of.031 inch diameter orifices are located rearwardly thereof, all on /2inch centers. In addition a pair of small lateral orifices (in oppositesides of the needle) are spaced 1 inch further toward the shank of theneedle. The total number of orifices recommended are as follows:

The following examples illustrate the benefits of the inventions.

EXAMPLE I Turkey breasts were removed from carcasses and separated intothree test lots. An emulsion comprising 84% coconut oil, 12% water, 3%salt, and 1% emulsifier, flavoring and color was prepared. Each breastof a first lot was injected with an amount of emulsion equaling 9% ofthe breast weight by inserting a single needle, having multipleorifices, into the Pectoralis superficialis musicle without penetratingthe skin and generally normal to the tissue fibers. The second and thirdlots of breasts were injected by multiple needles inserted through theskin and injecting amounts of emulsion equaling 7% and 9%, respectively,of each breast weight. All of the breasts were roasted under identicalconditions at 325 F. oven temperature for 3 hours 25 minutes to aninternal temperature of 175 F. The breasts of lot 1, injected accordingto this invention, displayed a cooking shrink (weight loss) of only20.7% from the injected weight, whereas the breasts of lots 2 and 3,injected by needles inserted through the skin were found to have aweight loss of 21.2% and 26.7%, respectively.

Examination for taste and tenderness showed a marketed preference forthe breasts injected at the higher percentage levels with somesuperiority noted for the breasts of lot 1. Testers recognized benefiitover untreated turkey breasts meat and found the cooked flesh of eachinjected breast to be uniformly affected throughout.

These data demonstrate that a relatively larger proportion of theemulsion injected according to the present invention (lot 1) is retainedin the tissue throughout cooking than where injected through the skin;and at higher, preferred levels of injection, breasts injected inaccordance with the invention have a significantly lower cooking shrink.

EXAMPLE II A whole turkey weighing approximately 11 lbs. was injectedwith 3% by weight of the emulsion described in Example I. The emulsionwas divided into two equal parts and injected by fractions into eachbreast by inserting a hollow-multiple orifice needle through thePectoralis superficials muscles from the posterior incision toward thewishbone. The needle was inserted twice in one breast and three times inthe other breast. Thereafter the turkey was cooked (without stuffing) ina 325 F. oven for 4 hours 30 minutes and to internal breast and thightemperatures of and 184 F., respectively. Cooking shrink was found to be25.5%. Examination by eating showed no noticeable difference betweenmeat taken from the two breasts, both being pleasing and jelly andjudged superior to the flesh of untreated turkey.

Obviously many modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and, therefore, only such limitations should be imposedas are in dicated in the appended claims.

We claim:

1. An improved method for injecting a liquid additive into the flesh ofan eviscerated fowl having anterior and posterior incisions to improvethe eating qualities of the flesh thereof, said method comprising:exposing both the left and right breast tissues at one of saidincisions; penetrating the exposed flesh of each breast by inserting ahollow needle in a direction generally longitudinal of the fowl carcassand substantially parallel to the keelbone whereby the iquid additivewhen injected Will be expelled from a plurality of orifices exposedalong the sides of said needle in direction substantially parallel tothe fibers of said tissue; injecting a quantity of liquid additive intothe breast tissue by expelling same from said needle and distributingrelatively greater quantities of said liquid additive in the thickerportions of said tissue adjacent the crop area of the fowl; withdrawingthe needle from the flesh of the fowl; and covering the entry site madein the flesh of each breast by the needle with unperforated skin so asto hinder the injected material from oozing therefrom.

2. The method of claim 1 wherein the fowl is first at least partiallychilled.

3. The method of claim 2 wherein the legs of the fowl have been trussedand the flesh of the fowl is penetrated from the posterior thereof.

References Cited UNITED STATES PATENTS 3,366,491 1/1968 Schwall et al.99l07 HYMAN LORD, Primary Examiner

